// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Portions of this code based on Mozilla:
//   (netwerk/cookie/src/nsCookieService.cpp)
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2003
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Daniel Witte (dwitte@stanford.edu)
 *   Michiel van Leeuwen (mvl@exedo.nl)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "net/cookies/ParsedCookie.h"

#include "net/cookies/CookieConstants.h"
#include "base/strings/string_util.h"

namespace {

const char kPathTokenName[] = "path";
const char kDomainTokenName[] = "domain";
const char kExpiresTokenName[] = "expires";
const char kMaxAgeTokenName[] = "max-age";
const char kSecureTokenName[] = "secure";
const char kHttpOnlyTokenName[] = "httponly";
const char kPriorityTokenName[] = "priority";

const char kTerminator[] = "\n\r\0";
const int kTerminatorLen = sizeof(kTerminator) - 1;
const char kWhitespace[] = " \t";
const char kValueSeparator[] = ";";
const char kTokenSeparator[] = ";=";

// Returns true if |c| occurs in |chars|
// TODO(erikwright): maybe make this take an iterator, could check for end also?
inline bool CharIsA(const char c, const char* chars) {
  return strchr(chars, c) != NULL;
}
// Seek the iterator to the first occurrence of a character in |chars|.
// Returns true if it hit the end, false otherwise.
inline bool SeekTo(std::string::const_iterator* it,
                   const std::string::const_iterator& end,
                   const char* chars) {
  for (; *it != end && !CharIsA(**it, chars); ++(*it)) {}
  return *it == end;
}
// Seek the iterator to the first occurrence of a character not in |chars|.
// Returns true if it hit the end, false otherwise.
inline bool SeekPast(std::string::const_iterator* it,
                     const std::string::const_iterator& end,
                     const char* chars) {
  for (; *it != end && CharIsA(**it, chars); ++(*it)) {}
  return *it == end;
}
inline bool SeekBackPast(std::string::const_iterator* it,
                         const std::string::const_iterator& end,
                         const char* chars) {
  for (; *it != end && CharIsA(**it, chars); --(*it)) {}
  return *it == end;
}

// Validate whether |value| is a valid token according to [RFC2616],
// Section 2.2.
bool IsValidToken(const std::string& value) {
  if (value.empty())
    return false;

  // Check that |value| has no separators.
  std::string separators = "()<>@,;:\\\"/[]?={} \t";
  if (value.find_first_of(separators) != std::string::npos)
    return false;

  // Check that |value| has no CTLs.
  for (std::string::const_iterator i = value.begin(); i != value.end(); ++i) {
    if ((*i >= 0 && *i <= 31) || *i >= 127)
      return false;
  }

  return true;
}

// Validate value, which may be according to RFC 6265
// cookie-value      = *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )
// cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
//                      ; US-ASCII characters excluding CTLs,
//                      ; whitespace DQUOTE, comma, semicolon,
//                      ; and backslash
bool IsValidCookieValue(const std::string& value) {
  // Number of characters to skip in validation at beginning and end of string.
  size_t skip = 0;
  if (value.size() >= 2 && *value.begin() == '"' && *(value.end()-1) == '"')
    skip = 1;
  for (std::string::const_iterator i = value.begin() + skip;
       i != value.end() - skip; ++i) {
    bool valid_octet =
        (*i == 0x21 ||
         (*i >= 0x23 && *i <= 0x2B) ||
         (*i >= 0x2D && *i <= 0x3A) ||
         (*i >= 0x3C && *i <= 0x5B) ||
         (*i >= 0x5D && *i <= 0x7E));
    if (!valid_octet)
      return false;
  }
  return true;
}

bool IsControlCharacter(unsigned char c) {
    return (c >= 0) && (c <= 31);
}

bool IsValidCookieAttributeValue(const std::string& value) {
  // The greatest common denominator of cookie attribute values is
  // <any CHAR except CTLs or ";"> according to RFC 6265.
  for (std::string::const_iterator i = value.begin(); i != value.end(); ++i) {
    if (IsControlCharacter(*i) || *i == ';')
      return false;
  }
  return true;
}

}  // namespace

namespace net {

ParsedCookie::ParsedCookie(const std::string& cookie_line)
    : path_index_(0),
	domain_index_(0),
	expires_index_(0),
	maxage_index_(0),
	secure_index_(0),
	httponly_index_(0),
	priority_index_(0) {

	if (cookie_line.size() > kMaxCookieSize) {
		//VLOG(1) << "Not parsing cookie, too large: " << cookie_line.size();
		return;
	}

	ParseTokenValuePairs(cookie_line, 0);
	if (!pairs_.empty())
		SetupAttributes();
}

ParsedCookie::ParsedCookie()
	: path_index_(0),
	domain_index_(0),
	expires_index_(0),
	maxage_index_(0),
	secure_index_(0),
	httponly_index_(0),
	priority_index_(0) {	
}

ParsedCookie::~ParsedCookie() {
}

bool ParsedCookie::IsValid() const {
	return !pairs_.empty();
}

CookiePriority ParsedCookie::Priority() const {
	return (priority_index_ == 0) ? COOKIE_PRIORITY_DEFAULT : StringToCookiePriority(pairs_[priority_index_].second);
}

bool ParsedCookie::SetName(const std::string& name) {
	if (!IsValidToken(name))
		return false;
	if (pairs_.empty())
		pairs_.push_back(std::pair<std::string, std::string>(std::string(""), std::string("")));
	pairs_[0].first = name;
	return true;
}

bool ParsedCookie::SetValue(const std::string& value) {
	if (!IsValidCookieValue(value))
		return false;
	if (pairs_.empty())
        pairs_.push_back(std::pair<std::string, std::string>(std::string(""), std::string("")));
	pairs_[0].second = value;
	return true;
}

bool ParsedCookie::SetPath(const std::string& path) {
	return SetString(&path_index_, kPathTokenName, path);
}

bool ParsedCookie::SetDomain(const std::string& domain) {
	return SetString(&domain_index_, kDomainTokenName, domain);
}

bool ParsedCookie::SetExpires(const std::string& expires) {
	return SetString(&expires_index_, kExpiresTokenName, expires);
}

bool ParsedCookie::SetMaxAge(const std::string& maxage) {
	return SetString(&maxage_index_, kMaxAgeTokenName, maxage);
}

bool ParsedCookie::SetIsSecure(bool is_secure) {
	return SetBool(&secure_index_, kSecureTokenName, is_secure);
}

bool ParsedCookie::SetIsHttpOnly(bool is_http_only) {
	return SetBool(&httponly_index_, kHttpOnlyTokenName, is_http_only);
}

bool ParsedCookie::SetPriority(const std::string& priority) {
	return SetString(&priority_index_, kPriorityTokenName, priority);
}

std::string ParsedCookie::ToCookieLine() const {
	std::string out;
	for (PairList::const_iterator it = pairs_.begin();
		it != pairs_.end(); ++it) {
		if (!out.empty())
			out.append("; ");
		out.append(it->first);
		if (it->first != kSecureTokenName && it->first != kHttpOnlyTokenName) {
			out.append("=");
			out.append(it->second);
		}
	}
	return out;
}

std::string::const_iterator ParsedCookie::FindFirstTerminator(
	const std::string& s) {
	std::string::const_iterator end = s.end();
	size_t term_pos = s.find_first_of(std::string(kTerminator, kTerminatorLen));
	if (term_pos != std::string::npos) {
		// We found a character we should treat as an end of string.
		end = s.begin() + term_pos;
	}
	return end;
}

bool ParsedCookie::ParseToken(std::string::const_iterator* it,
	const std::string::const_iterator& end,
	std::string::const_iterator* token_start,
	std::string::const_iterator* token_end) {
	ASSERT(it && token_start && token_end);
	std::string::const_iterator token_real_end;

	// Seek past any whitespace before the "token" (the name).
	// token_start should point at the first character in the token
	if (SeekPast(it, end, kWhitespace))
		return false;  // No token, whitespace or empty.
	*token_start = *it;

	// Seek over the token, to the token separator.
	// token_real_end should point at the token separator, i.e. '='.
	// If it == end after the seek, we probably have a token-value.
	SeekTo(it, end, kTokenSeparator);
	token_real_end = *it;

	// Ignore any whitespace between the token and the token separator.
	// token_end should point after the last interesting token character,
	// pointing at either whitespace, or at '=' (and equal to token_real_end).
	if (*it != *token_start) {  // We could have an empty token name.
		--(*it);  // Go back before the token separator.
				  // Skip over any whitespace to the first non-whitespace character.
		SeekBackPast(it, *token_start, kWhitespace);
		// Point after it.
		++(*it);
	}
	*token_end = *it;

	// Seek us back to the end of the token.
	*it = token_real_end;
	return true;
}

void ParsedCookie::ParseValue(std::string::const_iterator* it,
	const std::string::const_iterator& end,
	std::string::const_iterator* value_start,
	std::string::const_iterator* value_end) {
	ASSERT(it && value_start && value_end);

	// Seek past any whitespace that might in-between the token and value.
	SeekPast(it, end, kWhitespace);
	// value_start should point at the first character of the value.
	*value_start = *it;

	// Just look for ';' to terminate ('=' allowed).
	// We can hit the end, maybe they didn't terminate.
	SeekTo(it, end, kValueSeparator);

	// Will be pointed at the ; seperator or the end.
	*value_end = *it;

	// Ignore any unwanted whitespace after the value.
	if (*value_end != *value_start) {  // Could have an empty value
		--(*value_end);
		SeekBackPast(value_end, *value_start, kWhitespace);
		++(*value_end);
	}
}

std::string ParsedCookie::ParseTokenString(const std::string& token) {
	std::string::const_iterator it = token.begin();
	std::string::const_iterator end = FindFirstTerminator(token);

	std::string::const_iterator token_start, token_end;
	if (ParseToken(&it, end, &token_start, &token_end))
		return std::string(token_start, token_end);
	return std::string();
}

std::string ParsedCookie::ParseValueString(const std::string& value) {
	std::string::const_iterator it = value.begin();
	std::string::const_iterator end = FindFirstTerminator(value);

	std::string::const_iterator value_start, value_end;
	ParseValue(&it, end, &value_start, &value_end);
	return std::string(value_start, value_end);
}

ParsedCookie::PairList ParsedCookie::ParseNameValuePairs(const std::string& cookie_line) {
	ParsedCookie parser;
	parser.ParseTokenValuePairs(cookie_line, 1000);
	return parser.pairs_;
}

// Parse all token/value pairs and populate pairs_.
void ParsedCookie::ParseTokenValuePairs(const std::string& cookie_line, int max_pair) {
	pairs_.clear();

	// Ok, here we go.  We should be expecting to be starting somewhere
	// before the cookie line, not including any header name...
	std::string::const_iterator start = cookie_line.begin();
	std::string::const_iterator it = start;

	// TODO(erikwright): Make sure we're stripping \r\n in the network code.
	// Then we can log any unexpected terminators.
	std::string::const_iterator end = FindFirstTerminator(cookie_line);

	for (int pair_num = 0; pair_num < kMaxPairs + max_pair && it != end; ++pair_num) {
		TokenValuePair pair;

		std::string::const_iterator token_start, token_end;
		if (!ParseToken(&it, end, &token_start, &token_end))
			break;

		if (it == end || *it != '=') {
			// We have a token-value, we didn't have any token name.
			if (pair_num == 0) {
				// For the first time around, we want to treat single values
				// as a value with an empty name. (Mozilla bug 169091).
				// IE seems to also have this behavior, ex "AAA", and "AAA=10" will
				// set 2 different cookies, and setting "BBB" will then replace "AAA".
				pair.first = "";
				// Rewind to the beginning of what we thought was the token name,
				// and let it get parsed as a value.
				it = token_start;
			}
			else {
				// Any not-first attribute we want to treat a value as a
				// name with an empty value...  This is so something like
				// "secure;" will get parsed as a Token name, and not a value.
				pair.first = std::string(token_start, token_end);
			}
		}
		else {
			// We have a TOKEN=VALUE.
			pair.first = std::string(token_start, token_end);
			++it;  // Skip past the '='.
		}

		// OK, now try to parse a value.
		std::string::const_iterator value_start, value_end;
		ParseValue(&it, end, &value_start, &value_end);

		// OK, we're finished with a Token/Value.
		pair.second = std::string(value_start, value_end);

		// From RFC2109: "Attributes (names) (attr) are case-insensitive."
		if (pair_num != 0)
			base::StringToLowerASCII(&pair.first);
		// Ignore Set-Cookie directives contaning control characters. See
		// http://crbug.com/238041.
		if (!IsValidCookieAttributeValue(pair.first) ||
			!IsValidCookieAttributeValue(pair.second)) {
			pairs_.clear();
			break;
		}

		pairs_.push_back(pair);

		// We've processed a token/value pair, we're either at the end of
		// the string or a ValueSeparator like ';', which we want to skip.
		if (it != end)
			++it;
	}
}

void ParsedCookie::SetupAttributes() {
	// We skip over the first token/value, the user supplied one.
	for (size_t i = 1; i < pairs_.size(); ++i) {
		if (pairs_[i].first == kPathTokenName) {
			path_index_ = i;
		}
		else if (pairs_[i].first == kDomainTokenName) {
			domain_index_ = i;
		}
		else if (pairs_[i].first == kExpiresTokenName) {
			expires_index_ = i;
		}
		else if (pairs_[i].first == kMaxAgeTokenName) {
			maxage_index_ = i;
		}
		else if (pairs_[i].first == kSecureTokenName) {
			secure_index_ = i;
		}
		else if (pairs_[i].first == kHttpOnlyTokenName) {
			httponly_index_ = i;
		}
		else if (pairs_[i].first == kPriorityTokenName) {
			priority_index_ = i;
		}
		else {
			/* some attribute we don't know or don't care about. */
		}
	}
}

bool ParsedCookie::SetString(size_t* index,
	const std::string& key,
	const std::string& value) {
	if (value.empty()) {
		ClearAttributePair(*index);
		return true;
	}
	else {
		return SetAttributePair(index, key, value);
	}
}

bool ParsedCookie::SetBool(size_t* index,
	const std::string& key,
	bool value) {
	if (!value) {
		ClearAttributePair(*index);
		return true;
	}
	else {
		return SetAttributePair(index, key, std::string());
	}
}

bool ParsedCookie::SetAttributePair(size_t* index,
	const std::string& key,
	const std::string& value) {
	if (!(IsValidToken(key) && IsValidCookieAttributeValue(value)))
		return false;
	if (!IsValid())
		return false;
	if (*index) {
		pairs_[*index].second = value;
	}
	else {
		pairs_.push_back(std::make_pair(key, value));
		*index = pairs_.size() - 1;
	}
	return true;
}

void ParsedCookie::ClearAttributePair(size_t index) {
	// The first pair (name/value of cookie at pairs_[0]) cannot be cleared.
	// Cookie attributes that don't have a value at the moment, are represented
	// with an index being equal to 0.
	if (index == 0)
		return;

	size_t* indexes[] = { &path_index_, &domain_index_, &expires_index_,
		&maxage_index_, &secure_index_, &httponly_index_,
		&priority_index_ };
	for (size_t i = 0; i < arraysize(indexes); ++i) {
		if (*indexes[i] == index)
			*indexes[i] = 0;
		else if (*indexes[i] > index)
			--*indexes[i];
	}
	pairs_.erase(pairs_.begin() + index);
}

}  // namespace
